奇速英语

夏日误区揭秘：阳光下，你的维生素D真的足够吗？

Since it’s summer time, you might assume you will get enough vitamin D from the sun. But that is likely not the case. Vitamin D insufficiency now is thought to affect 30 to 50 percent of the world’s population.

The main source of vitamin D for most people is the sun, but achieving adequate levels of vitamin D via sunlight can be difficult depending on your geographical location, skin color, and age. Even if you live in a warm climate, you may not make enough vitamin D from sunlight alone. In a study of Hawaii residents who reported an average of 29 hours of sun exposure per week, half had vitamin D levels below 30 ng/ml. The only way to know for sure if you’re getting enough vitamin D is to have a 25(OH)D blood test. The scientific evidence supports a favorable range of 25(OH)D levels between approximately 30 and 45 ng/ml.

Adequate stores of vitamin D help prevent rickets in children and osteoporosis in older adults. But, there are other critical health benefits, too. Vitamin D insufficiency is thought to be a key contributor to many diseases, including several cancers, diabetes, cardiovascular disease, depression, and autoimmune diseases. If you need further evidence of how important vitamin D is, consider this: Scientists have found that it has biological actions in almost every cell and tissue in the human body.

How much vitamin D do you need? First, I recommend taking vitamin D3 which is the natural form of the vitamin and a higher-quality supplement (补充) compared to vitamin D2. Take a consistent daily dose of vitamin D3 aiming to achieve a 25(OH)D level that is between 30 to 45 ng/ml. If you do not supplement, it makes sense to have your 25(OH)D levels tested; take a positive attitude to your health, because a long-standing insufficiency can be harmful. Importantly, more vitamin D is not necessarily better; a 25(OH)D above approximately 45 ng/ml does not provide any further benefit and may even be harmful. Visit DrFuhrman.com for more information on the importance of Vitamin D.